Green-Mode PWM Controller with High Voltage Startup Circuit

Features

l High-Voltage (650V) Startup Circuit

l Very Low Startup Current (<30uA)

l Under-Voltage Lockout (UVLO)

l 100mW Standby Power

l Non-Audible-Noise Green-Mode Control

l 65KHz Switching Frequency with Jittering for Reducing EMI

l Cycle-by-Cycle Peak Current Limiting

l Internal Leading-Edge Blanking

l Internal Slope Compensation

l Gate Output Maximum Voltage Clamp 

l Internal 6mS Soft Start

l Soft Driving for Reducing EMI

l AC Input Brownout Protection with Hysteresis 

l Over-Voltage Protection (OVP) on VCC pin

l Over-Load Protection (OLP)

l External Shutdown Pin (Latch) for Aux. Winding OVP and Accuracy OTP

l 500mA Driving Capability

       l SOP-8 /SOP-7/DIP-8 Green Package

Description

The GR8875NR series is a highly-integrated, low startup current, current mode PWM controller with

Green-mode function, high-voltage startup circuit, and provides several protections such as OLP, OVP, and OCP for fault conditions. A high-voltage current source supplies the startup current and the traditional start up resistance can be saved in order to reduce the startup power loss.  The controller also includes the leading-edge blanking of the current sensing, internal slope compensation and cycle-by-cycle peak current limiting.  It is also integrated soft driving for reducing EMI, gate output voltage clamp function for protecting power MOSFET.

Applications

l Adaptor/ Open Frame Power Supply

l LCD Monitor/TV Power Supply

Application Circuit

Package